Serious reactions to peanut allergy: emergency medicine, 120 and what to do while waiting for the ambulance

Why can peanut allergy reactions come on fast and hard?

A serious reaction to peanut allergy is called an acute anaphylactic reaction in medical terms. It often starts within minutes of contact with the allergen, and in rare cases can start as late as about an hour afterwards. Once a reaction starts, it can get worse quickly, and in some cases the person can lose consciousness within a minute or two. This is not meant to frighten you; it is simply how this type of reaction behaves.

It often starts with a vague sense of unease, then tingling around the mouth, dizziness, itchy skin and raised welts. After that may come a tight throat, a hoarse voice, difficulty swallowing, wheezing, difficulty breathing, nausea and vomiting, pale skin, or bluish lips. Symptoms can appear together or one after another.

It is important to know that a serious reaction usually does not happen the first time someone eats peanuts; it more often appears after contact a second time. But many people cannot remember the first contact. So once a child is judged to have peanut allergy, the home should be prepared for "a serious reaction may happen", rather than waiting until something goes wrong to think about it.

What to do first: use the prescribed emergency medicine, call 120 (the emergency number in China), do not wait

If the child shows the signs of a serious reaction described above, the first step is to use the adrenaline auto-injector that the doctor has prepared for the child in advance, injecting into the site and in the way you have been taught. These devices are usually carried at all times, and the instructions are printed on the side of the device. Do not hold back because the symptoms still look mild; a serious reaction cannot be delayed.

The second step is to call 120 (the emergency number in China) immediately and say clearly "suspected acute anaphylaxis". At the same time, tell the operator how old the child is, what they ate, and that the emergency medicine has already been used. Do not drive the child yourself; the situation may change on the way, and the ambulance has the equipment for further treatment.

The third step is to stop the child from standing up or walking around, even if they feel a little better. Standing and walking can make blood pressure drop further. Lay the child down and you can raise their legs; if breathing is difficult, let them sit up slowly or raise their shoulders. For a pregnant person or an older child, follow the position the doctor has advised.

If five minutes pass and the symptoms have not improved, consider a second use of the emergency device according to the plan the doctor has given in advance. How many times to use it and how far apart is based on the child's written emergency plan; do not increase the dose yourself.

While waiting for the ambulance, what position and what to watch for?

While waiting, keep the child calm. Do not give water or food, and do not try to make them vomit. Loosen the collar and any tight clothing, and keep the air around them moving. If they vomit, turn the child's head to one side to prevent choking.

Watch their breathing and consciousness. Look at whether the chest is moving with effort, whether there is wheezing or a tight-throat sound, and whether they can speak in full sentences. Look at the colour of the face, lips and nails; for a child with darker skin, look at the palms and soles. Look for whether the child suddenly becomes very sleepy, responds more slowly, or cannot be woken.

If the child stops breathing or does not respond, start CPR immediately and tell the 120 operator, following the dispatcher's instructions. Having someone at home who knows first aid is far more reassuring than learning it after the ambulance arrives.

Even if symptoms ease, do not relax straight away: watch for a second reaction

After a serious reaction has been treated, symptoms can come back hours later; in medical terms this is called a biphasic reaction. It may be milder than the first reaction, or it may be worse. So even if the child clearly improves after adrenaline (epinephrine), they must still go to the emergency department and be observed by a doctor for several hours.

Before leaving the hospital, check that the emergency device has been replaced, that the written emergency plan has been updated, and that family members and the school all know how to use it. When the child goes out, the device should be carried on them, not left in a suitcase or in the car.

What you can do day to day is help the child and the family recognise the early signs, know where the device is kept and how to use it, and leave a written plan at school and at any childcare setting. Avoidance is still the foundation, but being well prepared means you will not panic when something happens.

When must you go to hospital straight away?

If any one of the following appears, treat it as a serious reaction, use the emergency medicine and call 120 (the emergency number in China): sudden swelling of the lips, tongue, mouth or throat; a tight throat, difficulty swallowing, or a hoarse voice; very fast or difficult breathing, wheezing, or a feeling of suffocation; blue, grey or pale skin, tongue or lips; sudden confusion, drowsiness or dizziness; the child is floppy and not responding as usual.

There is one more thing that is easy to miss: raised welts and itching on the skin together with vomiting, abdominal pain or dizziness should also be treated as a serious reaction. A rash is not a reliable guide to how serious a reaction is; in some serious reactions the rash is not obvious.

If there are only a few small red spots around the mouth and mild itching, with none of the signs above, it is still advisable to contact a doctor for advice and not to decide on your own. Whether it is a serious reaction and how to observe afterwards needs a doctor to decide based on the child's situation.

This article is for general information only and is not medical advice. Please follow your doctor's instructions.